JPS61135062A - Generating system of fuel cell - Google Patents

Abstract

PURPOSE:To enable to operate fuel batteries with uniform output of each fuel cell, when numerous fuel cells are used together, by installing a fuel flow control valve and an air flow control valve at each fuel pipe and air pipe respectively. CONSTITUTION:When plural cells N formed by laminating cell units which consist of electrolyte matrixs, positive and negative electrodes, and grooved in interconnectors, are used together to form a large capacity of generating system, the fuel feeding pipe 11 and the fuel exhaust pipe 12 of each fuel cell N are connected to the parent feeding pipe 23 and the parent exhaust pipe 24 through a fuel flow control valve 27. In the same manner, the air feeding pipe 13 and the air exhaust pipe 14 are connected to the parent air feeding pipe 25 and the parent exhaust pipe 26 through an air flow control valve 28. Therefore, by the control of the valves 27 and 28, fuel and air can be fed evenly to each fuel cell, and, uniform output and efficient operation can be acquired.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a fuel cell power generation device using a plurality of fuel cells, and in particular to an improved means for adjusting the amount of hydrogen gas supplied to each fuel cell. The present invention relates to a fuel cell that has undergone the following steps.

[Technical background of the invention] A fuel cell converts the chemical energy of fuel into electrochemical
This is a device that directly converts the energy released during the oxidation reaction into electrical energy by oxidizing it with a process. Power generation plants using fuel cells are expected to achieve a thermal efficiency of 40 to 50% even on a relatively small scale, far exceeding new thermal power plants. In general, SOx is a pollution factor that has become a major social problem in recent years.

Power generation with extremely low NOX emissions! It does not require a large amount of cooling water because it does not include a combustion cycle, and has low vibration noise.In principle, high energy conversion efficiency can be expected, and there are few environmental problems such as noise and exhaust gas.
In addition, because it has features such as good responsiveness to load fluctuations, there are expectations and interest in research into its development and practical application.

A small-scale fuel cell power generation device of this kind has already been prototyped and is in the stage of experimental operation. However, the biggest key to the practical application of Taiyong Agriculture's fuel cell power generation device is its structure, workability, and transportation constraints.
Since we cannot expect a significant increase in the unit capacity of fuel cells,
This depends on how efficiently a large number of fuel cells can be arranged, how the installation space can be reduced, and how efficiently the connection system for fuel gas and power terminals can be made more efficient.

Now, a cross-sectional model diagram showing the principle of such a fuel cell is shown in the second section.
Shown in the figure. That is, an electrolyte layer 2 impregnated with an electrolytic solution such as phosphoric acid is interposed between the - set of porous electrodes 1 to form a single cell, and hydrogen gas H and air A are supplied to both end faces of the single cell. Supply continuously.

In this way, reaction products and reaction residues are continuously removed to the outside, so power generation can be continued for a long period of time.

Further, the basic configuration of such a fuel cell is as shown in FIG. 3. That is, a positive electrode 4 and a negative electrode 5 are arranged on both sides of an electrolyte matrix layer 3 to form a square plate-shaped unit cell, and in order to use this unit cell as a power generation device, a large number of unit cells are connected in series. Ink connectors 6 having grooves for supplying gas are disposed between these unit cells and are stacked alternately with the unit cells. This grooved interconnector 6 has
A plurality of grooves are provided on the two opposing edges,
- The hydrogen gas flow path 7, which uses a side groove as a flow path, and the air flow path 8, which uses a side groove as a flow path, are arranged in directions perpendicular to each other.

By the way, the fuel cell currently under development is
As shown in Figure <A>(B), a cell stack 9 is constructed by stacking a plurality of cells as described above in a square column shape, and manifolds 10 for supplying reaction gas are attached to the four circumferential sides of the cell stack 9. There is. This manifold 10 includes a hydrogen gas supply pipe 11, a hydrogen gas discharge pipe 12, and an air supply pipe 1, respectively.
3 and an air exhaust pipe 14 are connected, and hydrogen gas and air are designed to flow in the directions of arrows A and B within the cell stack 9. Further, although a higher operating temperature of the cell stack 9 is preferable in terms of reaction theory, it is desirable to maintain it at around 200'C due to constraints such as the heat resistance of the constituent materials and the vapor pressure of the electrolyte. Therefore, chilled water is circulated in the conduit buried in the cell stack 9 to cool down the heating at the time of starting the fuel cell and the heat generated during operation. That is, in this type of fuel cell, a cooling water supply pipe 15 and a cooling water discharge pipe 16 are arranged as shown in FIG. It's circulating. Furthermore, the output of the fuel N pond is direct current, and power terminals (positive electrode) 17 and power terminals (negative electrode) are arranged at the upper and lower ends of the cell stack 9.
18, and is led out of the tank 21 via a connecting conductor 19 and a bushing 20.

The contents of the fuel cell as described above are stored in the tank 21, and inside the tank 21□, a heat insulating material 22 is applied and nitrogen gas etc. is included.

[Problems with Background Art] By the way, in a fuel cell as shown in FIG. 4 (A>(B)), the unit capacity is proportional to the area of the unit cell and the number of its 8 layers. Porous electrode plates that make up single cells have to be manufactured to have a uniform thickness over the entire surface, which is expensive, and because they are made of brittle materials, lamination work is limited.Furthermore, it is difficult to achieve uniform tightening force over the entire surface. It is difficult to significantly increase the area due to constraints such as the difficulty of
Since there is a limit to the number of pieces due to transportation restrictions or lamination work restrictions, the capacity per 91 cellstuffs is 20
It is suppressed to 0 to 500kw. Therefore, in order to put the fuel cell power generation device into practical use, it is necessary to install several tens or hundreds of fuel cells.

Therefore, it is important to make the amount of hydrogen and air supplied to each fuel cell uniform in order to make the output characteristics of the fuel cells uniform. Generally, when a fluid is sent through a pipe, the flow rate is greatly influenced by the pipe resistance determined by the pipe length, pipe diameter, fluid velocity, etc. In other words, in a power generating apparatus configured with a large number of fuel cells as described above, it is inevitable that the amounts of hydrogen and air supplied to each fuel cell will not be the same due to the resistance of each pipe. For this reason, a problem arises in that it is not possible to obtain the initially expected output as a fuel cell power generation device.

[Object of the Invention] The present invention was proposed to solve the above-mentioned problems, and its purpose is to make the output characteristics of each fuel cell uniform by making the amount of hydrogen and air to each fuel cell the same. The object of the present invention is to provide a fuel cell power generation device that can obtain the expected output.

[Summary of the Invention] When a plurality of fuel cell power generation units are installed together, the fuel cell power generation device of the present invention is designed to adjust the flow rate of the fuel and air so that the fuel flow rate and air flow rate of each fuel cell unit are the same. A fuel flow rate control valve and an air flow control valve are incorporated into the fuel side pipe and air side pipe of the fuel cell power generation unit that branch from the supply pipe, respectively, so that a fluid flow m II tin can be generated.

[Embodiments of the Invention] A fuel cell power generation device according to the present invention has a plurality of fuel cells N arranged as shown in FIG. , a hydrogen gas flow rate control valve 27 is installed in the hydrogen gas supply pipe 11 when connecting to the hydrogen gas main supply pipe 23 and the hydrogen gas main discharge pipe 24, respectively.
Incorporate. Further, when connecting the air supply pipe 13 and the air discharge pipe 14 to the air parent supply pipe 25 and the air parent exhaust pipe 26, respectively, the air supply pipe 13 has an air flow! Incorporate the control valve 28.

In a fuel cell power generation device with such a configuration, the hydrogen flow rate and air flow rate to each fuel cell N can be adjusted independently, and therefore the hydrogen flow rate and air flow rate to each fuel cell N can be made the same. Thus, the output of each fuel cell N can be made uniform.

In the embodiments of the present invention described above, hydrogen and air flow! Although the 1 control valve is installed on the supply pipe side of the fuel cell N, the same effect can be obtained even if these flow rate control valves are installed on the discharge pipe side.

[Effect of the invention 1 As described above, according to the present invention, when a large number of fuel cells are installed together to form a large-capacity power generation device, each fuel cell can be operated at the same output without biasing the output. , which is advantageous in extending the life of the power generation equipment.

[Brief explanation of the drawing]

Fig. 1 is a piping diagram showing one embodiment of the fuel cell power generation device of the present invention, Fig. 2 is a cross-sectional model diagram showing the principle of the fuel cell, and Fig. 3 is a piping diagram showing an embodiment of the fuel cell power generation device of the present invention.
The figure is a perspective view showing the basic structure of a fuel cell, FIG. 4A is a plan view showing a schematic structure of a fuel cell currently under development, and FIG. 4B is a longitudinal sectional view thereof. N... Fuel cell, 1... Porous electrode, 2... Electrolyte layer, 3... Electrolyte matrix layer, 4... Positive electrode,
5... Negative electrode, 6... Grooved interconnector, 7...
Hydrogen gas channel, 8... Air channel, 9... Cell stack, 10... Manifold, 11... Hydrogen gas supply pipe, 12... Hydrogen gas discharge pipe, 13... Air supply Pipe, 14... Air discharge pipe, 15... Cooling water supply pipe, 1
6...Cooling water discharge pipe, 17...Power terminal (positive It)
, 18... Power terminal (negative electrode), 1... Connection conductor,
20... Bushing, 21... Tank, 22...
Insulating material, 23...Hydrogen gas parent supply pipe, 24...Hydrogen gas parent discharge pipe, 25...Air parent supply pipe, 26...Air parent discharge pipe, 27...Hydrogen gas flow rate control valve , 28...
・Air flow control valve. 7317 Agent Patent Attorney Kensuke Norichika (1 other person) i
J! ;1m Figure 2 Figure 4 (A)

Claims (1)

[Claims] A fuel cell in which a plurality of fuel cells are connected in parallel to a fuel gas main supply pipe and a discharge pipe, and an air main supply pipe and a discharge pipe to supply and discharge fuel gas and air from each fuel cell. In a power generation device, a fuel gas flow rate control valve is incorporated in a fuel gas supply pipe or a fuel gas discharge pipe of a fuel cell, and an air flow rate control valve is incorporated in an air supply pipe or an air discharge pipe of a fuel cell. Battery power generator.